How do I remove this "Copy to (null)" option?

Hi babai,

It looks like there may be a problem with the e-book reader app that you are trying to drag the ebook to. I would first suggest backing up your iPhone, which backs up the app data. Then delete the app and re-download it. Here are a few resources with more detailed information:

iCloud: iCloud storage and backup overview
https://support.apple.com/kb/PH12519?locale=en_US

Here’s what iCloud backs up:

• Purchase history for music, movies, TV shows, apps, and books

  Your iCloud backup includes information about the content you purchased, but not the purchased content itself. When you restore from an iCloud backup, your purchased content is automatically downloaded from the iTunes Store, App Store, or iBooks Store. Some types of content aren’t downloaded automatically in all countries, and previous purchases may be unavailable if they have been refunded or are no longer available in the store. For more information, see the Apple Support article iTunes in the Cloud, iTunes Match, and iTunes Radio availability. Some types of content aren’t available in all countries. For more information, see the Apple Support article What can I buy from the iTunes Store in my country?.

• Photos and videos on your iOS devices

  However, if you turn on iCloud Photo Library on your iOS device (iOS 8.1 or later) or Mac (OS X v10.10.3 or later), your photos and videos are already stored in iCloud, so they aren’t included in your iCloud backup.

• Device settings

• App data

• Home screen and app organization

Delete music, movies, apps, and other content from your iPhone, iPad, or iPod touch
https://support.apple.com/en-us/HT204343

Delete an app

Remove an app using the steps below:

1. Tap and hold on the app until it jiggles.
2. Tap the in the upper-left corner to delete.

You might be asked to confirm that you want to delete the app. If you see a pop-up that says, "Deleting [app name] will also delete all of its data," tap Delete.

Download your past purchases
https://support.apple.com/en-us/HT201272

Redownload an app

On an iPhone, iPad, or iPod touch

1. Tap App Store.
2. On an iPhone or iPod touch: Tap Updates, then tap Purchased.
   On an iPad: Tap Purchased.
3. Scroll to find the app that you want to download.
4. Tap the Download icon . After the app downloads, you can open it from your Home screen.

Redownload in-app purchases

Some in-app purchases like game currency or hints are consumable, which means that they run out as you use them. You can only restore non-consumable purchases. Learn more about in-app purchases.

Happy Holidays to you!